busybox: Fix cut with "-s" flag

This fixes and issue that allows blank lines to be incorrectly output
when the "-s" flag is included. This issue propogates into the
populate-volatile.sh script in initscripts. If a volatiles drop file
contains blank lines, a blank line will be included in combined users,
which will incorrectly result in a difference in the number of combined
users versus defined users. If this happens, the volatiles file will not
be executed.

(From OE-Core rev: dfbcf0581ab3dd47037726a7b8aa06f777792473)

(From OE-Core rev: 5f75aaf0489f40bd35cdd27322e4d1189e30a9e4)

Signed-off-by: Colin McAllister <colinmca242@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

meta/recipes-core/busybox/busybox/0001-cut-Fix-s-flag-to-omit-blank-lines.patch

@@ -0,0 +1,66 @@
+From 199606e960942c29fd8085be812edd3d3697825c Mon Sep 17 00:00:00 2001
+From: Colin McAllister <colinmca242@gmail.com>
+Date: Wed, 17 Jul 2024 07:58:52 -0500
+Subject: [PATCH 1/1] cut: Fix "-s" flag to omit blank lines
+
+Using cut with the delimiter flag ("-d") with the "-s" flag to only
+output lines containing the delimiter will print blank lines. This is
+deviant behavior from cut provided by GNU Coreutils. Blank lines should
+be omitted if "-s" is used with "-d".
+
+This change introduces a somewhat naiive, yet efficient solution, where
+line length is checked before looping though bytes. If line length is
+zero and the "-s" flag is used, the code will jump to parsing the next
+line to avoid printing a newline character.
+
+In addition, a test to cut.tests has been added to ensure that this
+regression is fixed and will not happen again in the future.
+
+Upstream-Status: Submitted [http://lists.busybox.net/pipermail/busybox/2024-July/090834.html]
+
+Signed-off-by: Colin McAllister <colinmca242@gmail.com>
+---
+ coreutils/cut.c     | 6 ++++++
+ testsuite/cut.tests | 9 +++++++++
+ 2 files changed, 15 insertions(+)
+
+diff --git a/coreutils/cut.c b/coreutils/cut.c
+index 55bdd9386..b7f986f26 100644
+--- a/coreutils/cut.c
++++ b/coreutils/cut.c
+@@ -152,6 +152,12 @@ static void cut_file(FILE *file, const char *delim, const char *odelim,
+ 			unsigned uu = 0, start = 0, end = 0, out = 0;
+ 			int dcount = 0;
+ 
++			/* Blank line? */
++			if (!linelen) {
++				if (option_mask32 & CUT_OPT_SUPPRESS_FLGS)
++					goto next_line;
++			}
++
+ 			/* Loop through bytes, finding next delimiter */
+ 			for (;;) {
+ 				/* End of current range? */
+diff --git a/testsuite/cut.tests b/testsuite/cut.tests
+index 2458c019c..0b401bc00 100755
+--- a/testsuite/cut.tests
++++ b/testsuite/cut.tests
+@@ -65,6 +65,15 @@ testing "cut with -d -f( ) -s" "cut -d' ' -f3 -s input && echo yes" "yes\n" "$in
+ testing "cut with -d -f(a) -s" "cut -da -f3 -s input" "n\nsium:Jim\n\ncion:Ed\n" "$input" ""
+ testing "cut with -d -f(a) -s -n" "cut -da -f3 -s -n input" "n\nsium:Jim\n\ncion:Ed\n" "$input" ""
+ 
++input="\
++
++foo bar baz
++
++bing bong boop
++
++"
++testing "cut with -d -s omits blank lines" "cut -d' ' -f2 -s input" "bar\nbong\n" "$input" ""
++
+ # substitute for awk
+ optional FEATURE_CUT_REGEX
+ testing "cut -DF" "cut -DF 2,7,5" \
+-- 
+2.43.0
+

meta/recipes-core/busybox/busybox_1.36.1.bb

@@ -56,6 +56,7 @@ SRC_URI = "https://busybox.net/downloads/busybox-${PV}.tar.bz2;name=tarball \
            file://0001-awk-fix-precedence-of-relative-to.patch \
            file://0002-awk-fix-ternary-operator-and-precedence-of.patch \
            file://0001-awk.c-fix-CVE-2023-42366-bug-15874.patch \
+           file://0001-cut-Fix-s-flag-to-omit-blank-lines.patch \
            "
 SRC_URI:append:libc-musl = " file://musl.cfg "
 # TODO http://lists.busybox.net/pipermail/busybox/2023-January/090078.html